The present invention concerns self-contained portable oxygen generators, also called concentrators, capable of providing oxygen with a purity of between 90 and 95%, by pressure adsorption in a PSA unit comprising at least one adsorber.
PSA units provide oxygen of which the purity depends on the consumption rate. Even with efficient adsorbents, a rapid fall in performance is found at high rates and a progressive but marked fall in performance at low rates.
In known self-contained oxygen generators, it has been proposed to adapt the production process to the oxygen consumption, in particular by temporarily stopping the PSA unit or by adapting the cycle time according to the rate at which the flow is consumed. Such systems necessitate the intervention of an operator and stabilization times are incompatible with the reactivity required by user patients.
The object of the present invention is to provide a self-contained oxygen generator avoiding the abovementioned disadvantages, in particular by not requiring modifications to the cycle time nor human interventions, with maintenance of a virtual steady state.